Emission electrodes intended for electrostatic precipitators will preferably exhibit a number of essential properties, such as high mechanical strength and rigidity, infrequent service requirements, high corrosion resistance and high efficiency, and will be capable of being manufactured and handled in a rational and efficient manner.
Electrostatic precipitators are used, for instance, to cleanse media in the form of, for instance, dust-laden gases eminating from sulphuric-acid production processes, metal smelting processes, cement manufacturing plants and incinerators.
Electrostatic precipitators can be constructed to cleanse both dry and moist gases from the dust carried thereby. Dry-gas precipitators are normally constructed for horizontal gas-throughflow, whereas moist-gas precipitators are normally constructed for vertical gas-throughflow.
In addition to the aforesaid emission electrodes, such electrostatic precipitators also include collector electrodes. A voltage source is provided for creating a potential difference between the emission electrodes and the collector electrodes, so as to generate an electric field between said electrodes in an area through which the dust-laden gas flows, the dust particles being caused primarily to settle on the collector electrodes, such that the gas exiting from the precipitator will be essentially free from dust particles.
The voltage applied in the case of such precipitators is preferably a direct voltage which preferably lies at the sparkover limit, i.e. such as to obtain the highest possible electric field-strength at which a corona effect and glowing-discharge will take place, therewith to provide the maximum precipitating force on the discrete dust particles and consequently to achieve the highest possible gas-cleansing effect.
Various kinds of such so-called rigid emission-electrodes are known to the art, all of which have a number of different drawbacks: These drawbacks are eliminated to a large extent by means of the inventive emission electrode.